For safety and stability, disconnect the AC input (grid/generator) and the AC output (your home loads). The inverter should be powered solely by the battery bank during the update to prevent a power surge or interruption. Step 2: Connect to the PC
For the average homeowner who just wants lights to turn on during a blackout, do not touch the firmware. For the solar enthusiast squeezing every drop of efficiency from a budget system, the Easun firmware update is the key to unlocking stalled potential. easun firmware update
| Symptom | Likely Cause | Solution | | :--- | :--- | :--- | | "Connection Failed" | Wrong COM port or cable lacks FTDI chip | Check Device Manager. Swap to a known-good RS232 cable. | | "Checksum Error" | Corrupted download file | Re-download the HEX file. Do not use a download manager. | | Inverter beeps continuously after flash | U1 and U2 mismatch | Re-flash the DSP with the correct version. You flashed Axpert firmware on an Easun. | | Black screen, fans running | Bricked bootloader | Hard recovery: Short the "Boot" jumper on the main board (pins 1-2) while powering on, then re-flash within 5 seconds. | | "Fault 21" after update | Bus voltage calibration lost | You need the factory calibration code (Setting 29 or secret menu: UP+DOWN+ENTER for 5 seconds). | For safety and stability, disconnect the AC input
: If the device isn't detected, check the Device Manager for triangle icons indicating missing drivers for your USB-to-serial converter. For the solar enthusiast squeezing every drop of